Presentation on theme: "On bad genes and how to detect them (Game from Univ. Utah)"— Presentation transcript:
1On bad genes and how to detect them (Game from Univ. Utah) Siguna MuellerPhD student in BMS, Univ. WyomingWill ask you to be detective to find bad gene. First, some basics.
2What is DNA? Each cell needs instructions for its role in the body What do these instructions look like?
3The instructions come in the form of a molecule called DNA. DNA encodes a detailed set of plans, like a blueprint for building different parts of the cellHave you seen blueprints before? For what? Instructions are often broken up into parts. E.g. to build a house: electricity, roofing, windows…
4What is a Gene? Genes are instruction manuals for our body. They are the directionsfor building all theproteins.Proteins make ourbodies function.Each gene is responsible for its own protein product. How would that relate to our house?
5What do genes look like? Genes are made of DNA. One strand of DNA contains many genes.Each cell in our body contains a lot of DNA!How much?The DNA from a single human cell, if stretched out, would be 3 meters long! How long is that?
6How does all of that DNA fit into a cell? The DNA is packaged into compact units called chromosomes.Chromosomes are efficientstorage units for DNA.
7How many chromosomes does each cell have? Each HUMAN cell has 46 chromosomes.All the DNA is organized intotwo sets of 23chromosomes(2x23=46 total).We get genes from both our parentsThat’s why children look both like their mom and dad
8Remember Every human has the same set of genes. chromosomes Genes reside on chromosomes.Basic instruction as to how to build a house is the same. But houses are different. How?
9If we all have the same genes, what makes us different? The information carried on genes differ slightly from person to person.Different forms of genes (alleles)result in unique traitsExamples?9 chromosomesSimplify:Assume only 1 geneper chromosome
11MutationsA mutation is a permanent change to in the genetic material (seen in the DNA sequence).What are the consequences of a such a change?What would that mean for our house?
12(How) can a gene be responsible for a disease? Mutations may cause genes to malfunction.This is known as a genetic disorder.How?A gene is mutated when it causes its protein product to malfunction.Do you know an example of a genetic D/O?Neurofibromatosis I (NF1)NF1 affects 1 in 3,000 individuals. D/O of nervous system, causes tumor growth. The gene encodes a protein that is responsible for cell division. Too much cell division leads cancer.
13Genetic disorders A medical conditions only arises when the DNA sequence of agene is mutated.Not all changes in DNA sequences lead to faulty genes.So, how do scientists discover the faulty gene that is responsible for a medical condition?For NF 1: the faulty gene is on chromosome 17
14How to detect faulty genes Can we find out, on which chromosome?Once we know which chromosome, scientists can locate the faulty gene on this chromosome.Example: Bad applesHave a distinctive color
15Key for DiscoveryEvery person with the D/O has this particular faulty geneNO healthy individual has this faulty gene
16Suppose we only have 9 chromosomes. Each chromosome carries different information for different people.Indicated by different colorsOne of the four individual has a faulty gene.Which of the chromosomes is faulty?What and where is the ‘bad color’?
17Genetic disorders run in families What does this mean?Does every child get the D/O?How can we find out?Construct a pedigree:Diagram that describes family relationshipsShows which family member has the D/O
18A Pedigree of NF 1 Black circles or squares indicate disease Can ‘map’ gene to a specific location on the chromosomeKnow which gene -> this helps for therapy
19Unaffected Unaffected Unaffected Affected Other affectedThe green colored piece in the center is present inall affected individualsThe green is absent in individuals who do not havethe disorder